Weak universality in the two-dimensional randomly disordered three-state Potts ferromagnet

For the two-dimensional randomly disordered three-state Ports ferromagnet, we find numerically that the critical exponents of the correlation length nu, magnetic susceptibility gamma, and magnetization beta increase continuously with the strength of disorder, while the ratios gamma/nu and beta/nu remain unchanged (thus verifying the hyperscaling relation gamma+2 beta=D nu). Our finding indicates the presence of a certain universal feature valid in any disordered ferromagnet, which can be explained by the weak universality concept.